(11) EP 0 496 534 A3


(88) Date of publication A3:
24.02.1993 Bulletin 1993/08

(43) Date of publication A2:
29.07.1992 Bulletin 1992/31

(21) Application number: 92300400.6

(22) Date of filing: 17.01.1992
(51) International Patent Classification (IPC)5G06F 1/26
(84) Designated Contracting States:

(30) Priority: 25.01.1991 US 646304

(71) Applicant: International Business Machines Corporation
Armonk, N.Y. 10504 (US)

(72) Inventors:
  • Katz, Neil Alan
    Parkland, Florida 33067 (US)
  • Pollitt, Richard Francis
    Jensen Beach, Florida 34957 (US)
  • Suarez, Leopoldo Lino
    Boca Raton, Florida 33487 (US)
  • Frank, Charles William
    Irvine, California 92720 (US)

(74) Representative: Burt, Roger James, Dr. 
IBM United Kingdom Limited Intellectual Property Department Hursley Park
Winchester Hampshire SO21 2JN
Winchester Hampshire SO21 2JN (GB)

(56) References cited: : 

    (54) Battery operated personal computer

    (57) A battery operated portable personal computer includes ambient temperature (46) and humidity (48) sensors, as well as two LCD's (52) to provide visual indication that the ambient temperature or humidity is out of range. If the ambient temperature drops below 3 degrees C, or if it rises above 52 degrees C, the computer enters a low power suspend mode wherein the computer is inoperable, but, upon switching from the suspend mode to the resume (operating) mode, the application program that was running at the time of the suspension is resumed at the same point that the suspension occurred. The LCD temperature indicator is activated when the ambient temperature drops below 3 degrees C, or rises above 46 degrees C. Thus, for high temperatures, the temperature indicator is activated 6 degrees before the computer is placed in the suspend mode. The ambient temperature is periodically monitored while in the suspend mode and, if the temperature rises above 6 degrees C, or drops below 44 degrees C, the computer switches from suspend to resume. Thus, hysteresis is provided to prevent the computer from oscillating between suspend and resume modes. If the humidity rises above 96% relative humidity, the computer enters the suspend mode and the LCD humidity indicator is activated. The ambient humidity is periodically monitored in the suspend mode and, if it drops below 87% relative humidity, the computer switches from suspend to resume mode.

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